Automatic Device for Feeding Plastic Film for Packaging Machines

ABSTRACT

An automatic device ( 1 ) is described for feeding a plastic film ( 4 ) for packaging machines ( 12 ) with miscellaneous products comprising means for feeding the plastic film ( 4 ); gripping and transporting means of the plastic film ( 4 ) comprising at least one dragging belt ( 5 ) adapted to get in contact with the plastic film ( 4 ) and to drag it in a packaging area ( 6 ) of the packaging machine ( 12 ); and command and control means adapted to unwind the plastic film ( 4 ) from the feeding means.

CROSS REFERENCE TO RELATED APPLICATION

The present Application claims priority from Italian Patent ApplicationNo. T02005U000103 titled “Automatic Device for Feeding Plastic Film forPackaging Machine,” filed Jul. 22, 2005, the contents of which areincorporated in this disclosure by reference in their entirety.

FIELD

The present invention refers to an automatic device for feeding plasticfilm for packaging machines with miscellaneous products.

BACKGROUND

Numerous embodiments are known in the art of machines for packagingproducts in an extensible plastic film adapted to completely close theproduct to be packaged, possibly contained in a supporting tank, in thefilm itself.

In particular, Applicant's International Patent ApplicationPCT/IT2003/000256 (Publication WO 2004/048201 A1) discloses a packagingmachine equipped with a packaging head oscillating with a swingingmovement adapted to put in contact the plastic film with the product tobe packaged and to adhere the film itself to the product in a stretchedposition; such packaging head is further equipped with means for feedingthe plastic film, such as, for example, a coil, from which the plastidfilm is manually unwound for an adequate length for packaging, so that,by lowering the packaging head, the plastic film gets in contact withthe product to be packaged in a packaging area of the head itself. Itis, however, evident that the manual unwinding of the plastic film canhave some inconveniences, resulting in a critical activity for thepackaging machine operation, since it can create, for example, theslowing down of packaging operations or prevent the completely automaticoperation of the device.

In order to solve this type of inconveniences, known packaging machinescan be equipped with systems for moving the plastic film with suitablyactuated gripping collets: these systems, however, require the creationof very complex and extremely costly automatic mechanisms both forgripping the plastic film and for their adjustment depending on thewidth of the used film.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is solving the above priorart problems by providing an automatic device for feeding plastic filmfor packaging machines with miscellaneous products which can be easilymanufactured and operated, which is more inexpensive and simpler thanwhat is proposed by the prior art.

The above and other objects and advantages of the invention, as willresult from the following description, are obtained with an automaticdevice for feeding plastic film for packaging machines withmiscellaneous products as described in claim 1. Preferred embodimentsand non-trivial variations of the present invention are the subjectmatter of the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better described by some preferredembodiments thereof, provided as a non-limiting example, with referenceto the enclosed drawings, in which:

FIG. 1 shows a perspective view of a packaging head equipped with anembodiment of the automatic device for feeding plastic film forpackaging machines with miscellaneous products according to the presentinvention; and

FIG. 2 shows a side view of a packaging machine equipped with thepackaging head of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

In the following description, the term “product” will designate both anindividual object or element to be packaged (for example, in thefoodstuff field), and the same object or element placed in a vessel,tank or the like, for packaging the whole assembly.

With reference to the Figures, a preferred embodiment of the device 1according to the present invention is described, such device beingapplied as an example to a packaging head 10 of a packaging machine 12like the one described in the previously mentioned WO 2004/048201, butit is wholly obvious that numerous variations and modifications can bemade to the device, in order to adapt it to different packaging machineswithout departing from the scope of the invention.

With reference therefore to FIGS. 1 and 2, it is possible to note thatthe automatic device 1 for feeding a plastic film 4 for packagingmachines with miscellaneous products comprises means for feeding theplastic film 4, such as, for example, at least one coil 8, and grippingand transporting means, actuated by command and control means, adaptedto continuously and automatically unwind the plastic film 4 from itsfeeding means, in order to take it to a packaging area 6 of thepackaging machine 12.

In particular, the gripping and transporting means comprise at least onedragging belt 5 of the film 4 (the embodiment of the device 1 shown inthe Figures is preferably equipped with two parallel dragging belts 5sliding on the packaging area 6 sides) made of plastic or rubberymaterial or another material coated with plastic or rubbery material,preferably having a mirror polished surface aimed to get in contact withthe plastic film 4 and to create with this latter one a slight gluing,mentioned below, for dragging it in the packaging area 6 of thepackaging machine 12. Obviously, the dragging belts 5 can be in adifferent number from two and with variable length.

The command and control means comprise at least one first and one secondrotating shaft, respectively 11, 13, which allow rotating the draggingbelts 5 and suitably arranged in order to be able to drag the plasticfilm 4 on the packaging area 6 of the packaging machine 12, the firstrotating shaft 11 being the drive shaft driven by a motor 15, preferablyof the electric type, which drags the dragging belts 5.

When unwinding the plastic film 4 from the coil 8, the film 4 itself islaid onto the dragging belts 5 by passing through at least one pressingrubbery roller 7 which, by pressing against the first rotating shaft 11,allows a slight gluing of the plastic film 4 on the surface of thedragging belts 5; glueing, adapted for dragging the plastic film 4 bythe dragging belts 5, occurs by means of a natural cohesion between theplastic film 4 and the polished surface of the dragging belts 5 byremoving interposed air and is enabled by the pressure which thepressing rubbery roller 7 exerts against the dragging belts 5 polishedsurface.

The command and control means can also comprise adjusting systems, suchas, for example, an Encoder (not shown), which adjust the unwoundplastic film 4 length by detecting the angular positions of the firstrotating shaft 11 and by means of the motor 15 allows unwinding acertain length of the plastic film 4 from the feeding means; the Encoderin fact allows actuating the motor 15 for a number of revolutions setaccording to the desired length of the plastic film 4 to be unwound.

Naturally, the managing and control means can comprise, as replacementfor the Encoder, other adjusting systems for the plastic film 4 lengthoperating by means of micro-switches actuated by variable abutments ortimers with adjustable time.

Therefore, when the product is arranged in the packaging machine 12 nextto the packaging area 6, the managing and control means actuate themotor 15 which rotates the first rotating shaft 11 for such a number ofrevolutions as to allow unwinding from the coil 8 an adequate length ofplastic film 4; due to gluing between dragging belts 5 and plastic film4 enabled by the pressing rubbery roller 7, the plastic film 4 is takento the packaging area 6 above the product to be packaged; by thenlowering the packaging head 10, the product is packaged and the plasticfilm 4 is cut in the proper and known modes of the packaging machine 12;by lifting the packaging head 10 again, the managing and control meansagain actuate the motor 15 for unwinding from the coil 8 anotheradequate length of plastic film 4, bringing back the packaging machine12 ready to perform a new packaging.

Although the present invention has been discussed in considerable detailwith reference to certain preferred embodiments, other embodiments arepossible. Therefore, the scope of the appended claims should not belimited to the description of preferred embodiments contained in thisdisclosure. All references cited herein are incorporated by reference totheir entirety.

1. An automatic device for feeding a plastic film for packaging machineswith miscellaneous products wherein the automatic device comprises: a)means for feeding the plastic film; b) gripping and transporting meansof the plastic film comprising at least one dragging belt adapted to getin contact with the plastic film and to drag it in a packaging area ofthe packaging machine; and c) command and control means adapted tounwind the plastic film from the feeding means.
 2. The device of claim1, wherein the feeding means comprise at least one coil.
 3. The deviceof claim 1, wherein the dragging belt is made of plastic or rubberymaterial.
 4. The device of claim 1, wherein the dragging belt is coveredwith plastic or rubbery material.
 5. The device of claim 1, wherein thedragging belt has a mirror polished surface for contacting the plasticfilm.
 6. The device of claim 1, wherein the command and control meanscomprise at least one first and one second rotating shaft, the firstrotating shaft being driven by a motor for rotating the dragging belts.7. The device of claim 1, wherein the command and control means comprisea system for adjusting a length of the unwound plastic film.
 8. Thedevice of claim 7, wherein the adjusting system comprises an Encodercooperating with the motor.
 9. The device of claim 7, wherein theadjusting system comprises micro-switches actuated by variableabutments.
 10. The device of claim 7, wherein the adjusting systemcomprises timers with variable time.
 11. The device of claim 1, whereinthe gripping and transporting means comprise a pressing rubbery rollercooperating with the first rotating shaft for gluing the plastic film tothe dragging belts.
 12. The device of claim 6, wherein the gripping andtransporting means comprise a pressing rubbery roller cooperating withthe first rotating shaft for gluing the plastic film to the draggingbelts.